Electrical and thermal conductivity of AIN ceramics doped with beryllium and oxygen

Groen, W.A.; Lierop, J.G. van; Roosen, Andreas

doi:10.1007/bf00274507

Cited by 9 publications

(5 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3 Furthermore, the deep character of O N in AlN explains the fact that even a large oxygen concentration does not lead to n-type conductivity, and that AlN remains insulating with a high activation energy ͑over 2.0 eV͒ necessary for electrical conductivity. 34 The positive and neutral charge states of O N in AlN are found to stay on site, as shown in Table II. The negative charge states move to off-center position, similarly to the FIG.…”

Section: Oxygen In Alnmentioning

confidence: 88%

“…This resembles the observed behavior for O N , and agrees with the experimental observation of the high activation energies needed for electrical conductivity. 34 The triply negative Al vacancy is seen to be easily created when the Fermi level is around midgap or higher. Thus V Al 3Ϫ and O N ϩ are seen to be the most favorable oppositely charged defects to be formed when the Fermi level is somewhat above the midgap.…”

Section: Oxygen In Alnmentioning

confidence: 99%

See 1 more Smart Citation

Abinitiostudy of oxygen point defects in GaAs, GaN, and AlN

1996

View full text Add to dashboard Cite

We have studied oxygen point defects with the plane-wave pseudopotential method in GaAs, GaN, and AlN. The calculations demonstrate a qualitatively different behavior of oxygen impurities in these materials. O As in GaAs acts as a deep center with an off-center displacement and negative-U behavior, in agreement with the experimental data. O N in GaN is found to be a shallow donor with a low formation energy, and is suggested to act as a partial source for the unintentional n-type conductivity commonly observed in GaN. O in AlN is also found to easily substitute for N, which is consistent with the experimentally observed large oxygen concentrations in AlN. However, O N in AlN is shown to be a deep center due to the wide band gap, in contrast with O N in GaN. Our calculations thus predict that isolated oxygen acts as a DX-type center in Al x Ga 1Ϫx N alloys. Results for other oxygen point defect configurations and for the dominant native defects are also presented.

show abstract

Section: Oxygen In Alnmentioning

confidence: 88%

Section: Oxygen In Alnmentioning

confidence: 99%

Abinitiostudy of oxygen point defects in GaAs, GaN, and AlN

1996

View full text Add to dashboard Cite

show abstract

“…In order to enhance the densification and thermal conductivity, sintering aids are commonly added to AlN. It has been reported that these additives also affect the electrical resistivity of AlN ceramics because they produce second phases at grain boundaries, or generate or annihilate defects in AlN grains 3–7 . However, these studies are limited to several compositions, and studies for other compositions have been expected.…”

Section: Introductionmentioning

confidence: 99%

Effects of Samarium Oxide Addition on the Phase Composition, Microstructure, and Electrical Resistivity of Aluminum Nitride Ceramics

Yoshikawa

Katsuda

Yamada

et al. 2005

Journal of the American Ceramic Society

View full text Add to dashboard Cite

The phase composition, microstructure, and electrical resistivity of hot-pressed AlN ceramics with 0-4.8 wt% Sm 2 O 3 additive were investigated. The phase composition was approximately consistent with that estimated from the Sm 2 O 3 -Al 2 O 3 phase diagram using the amount of added Sm 2 O 3 and oxygen content of the AlN raw material. When sintered at more than 18001C, the AlN ceramics with 1.0-2.9 wt% Sm 2 O 3 additive contained an Sm-b-alumina phase wetting the grain boundaries, and their electrical resistivity considerably decreased to 10 10 -10 12 X . cm. This resistivity decrease was caused by the continuity of the Smb-alumina phase with a resistivity lower than that of bulk AlN.

show abstract

“…The high oxygen concentration in the AlN layers is caused by high reactivity between Al and O and the diffusion of oxygen atoms from the substrate, however it has been reported that the O can move from being a shallow donor in GaN to a deep electron trap in AlN, and can become not only acceptors (O N ‐) but donors (O N +). As a consequence, the AlN is almost always insulating, with a high activation energy (>2 eV) . In the GaN layers, oxygen distribution is nearly the same as that in samples C and D, however carbon concentration [C] increases considerably in the GaN layers (both above and below the HT AlN IL), especially in the HT AlN interlayer and in the HLHT AlN buffer.…”

Section: Resultsmentioning

confidence: 90%

Barrier Strain and Carbon Incorporation‐Engineered Performance Improvements for AlGaN/GaN High Electron Mobility Transistors^**

Luong

Tran

et al. 2014

Chemical Vapor Deposition

View full text Add to dashboard Cite

The improvements in electrical characteristics of AlGaN/GaN high electron mobility transistors (HEMTs) grown using metalorganic (MO)CVD by engineering structure, barrier strain, and unintentional carbon incorporation, are demonstrated in this work. Both normal HEMT structure (with a high temperature (HT) AlN buffer) and advanced HEMT structure (with a highlow-high temperature (HLHT) AlN buffer, and a HT AlN interlayer (IL)) present a breakdown voltage higher than 200 V, while a much smaller breakdown voltage of 17 V is measured on the conventional structure using a low-temperature GaN buffer. The HT AlN IL inserted in the middle of the conventional HEMT structure introduces a reduction in the tension of the AlGaN barrier, which results in an improvement of the surface morphology (0.46 nm). As a consequence, the two-dimensional electron gas (2DEG) mobility increases by remarkable 46% (1900 cm 2 V À1 s À1 ). The HLHT AlN buffer, substituting for the HT AlN buffer, leads to the enhancement of GaN crystalline quality, which contributes to the performance improvement for HEMTs. The advanced HEMT, using both an AlN IL and an HLHT AlN buffer, produces increases in the DC maximum drain current by 35.5% ($680 A mm À1 ), and in the transconductance by 15% (114 mS mm À1 ) in comparison with the normal HEMT with an AlN buffer. The very low leakage current in the advanced HEMTs is caused by optimizing the design of the buffer and modifying growth parameters. Lastly, the reduction of AlGaN barrier tensile strain by inserting the HT AlN IL is promising for an improvement in AlGaN/GaN HEMT reliability.

show abstract

Electrical and thermal conductivity of AIN ceramics doped with beryllium and oxygen

Cited by 9 publications

References 9 publications

Abinitiostudy of oxygen point defects in GaAs, GaN, and AlN

Abinitiostudy of oxygen point defects in GaAs, GaN, and AlN

Effects of Samarium Oxide Addition on the Phase Composition, Microstructure, and Electrical Resistivity of Aluminum Nitride Ceramics

Barrier Strain and Carbon Incorporation‐Engineered Performance Improvements for AlGaN/GaN High Electron Mobility Transistors^**

Contact Info

Product

Resources

About

Electrical and thermal conductivity of AIN ceramics doped with beryllium and oxygen

Cited by 9 publications

References 9 publications

Abinitiostudy of oxygen point defects in GaAs, GaN, and AlN

Abinitiostudy of oxygen point defects in GaAs, GaN, and AlN

Effects of Samarium Oxide Addition on the Phase Composition, Microstructure, and Electrical Resistivity of Aluminum Nitride Ceramics

Barrier Strain and Carbon Incorporation‐Engineered Performance Improvements for AlGaN/GaN High Electron Mobility Transistors**

Contact Info

Product

Resources

About

Barrier Strain and Carbon Incorporation‐Engineered Performance Improvements for AlGaN/GaN High Electron Mobility Transistors^**